Communicative pair activities are a sticky wicket in the TCI community. Some teachers love them while others eschew them as carryovers from their days as textbook teachers. Common complaints include (a), students obtaining the information they need in L1 instead of the target language and (b), boring topics that kids do not want to talk about.
In my experience, the problem with kids phoning in a task like this often stems from the fact that they are not interested in the answers that they are supposed to be looking for. Give them compelling and relevant details to learn about their classmates and they will want to know them. Make sure they have the language they need to ask and respond to the questions and your students will be much more likely to stay in the target language.
